Electron discharge tube and circuit arrangement therefor



1951 R. BONNE'ETAL ELECTRON DISCHARGE TUBE AND CIRCUIT ARRANGEMENT THEREFOR Filed May 2, 1947 2 SHEETSSHEET l 1 v IN VN TORS.

Robert l nfl ierre Cahour' 8 ierre iv t Nov. 6, 1951 R. BONNE ETAL 2,574,012

ELECTRON DISCHARGE TUBE AND CIRCUIT ARRANGEMENT THEREFOR Filed May 2, 1947 2 SHEETS-SHEEI 2 Patented Nov. 6, 1951 EEEGTRON'DISCHA-RGE TUBE AND CIRCUIT ARRANGEMENT THEREFOR Robert. Burma. Pi'erre- Cahour, and. Pierre G'rivet, Pari's Erance, assignors tocompagni'e Generale ,de Telegraphic Sans Fi'l; a corporation of France Application .May 2, 1947, Serial No. 745 628 In France-September 1942 Section 1", P.ubli'c Law 690, August 194s Patent expires September I5, 1962 eral preferred to ordinary triode ortetrodetubes for'the generation or amplification of very shortwaves such as d'eci'meter and centimeter waves butwhile they have the advantage of givinggreat power knownvel'ocity modulated tubes are much less convenient to use than ordinary tubes such as triodes on long waves for which use they present a number of disadvantages.

Firstly knowntubes of' the kind referred to incorporate oscillatory circuits in the form' of 7-'Glai.ms-.. (01. 3 15-6) resonant cavities which constitute part of the tube structure and oftenindeed constitute partof the evacuated envelope of the tube: Such a construction while presenti'ng material advantages for very short wavework-ing' also; however, has the following defects:

(1') A- resonant oscillatory ei'rcuitformingpart of the tube structure cannot be changed and the range of adjustment of operating" wave lengths is accordingly very small and involves mechanical or electrical distortion of the oscillatery circuit. This is difi'icult to achieve satisf'actor-ily if the circuit forms an integral part of the envelope structure.

(2) Such tubes cannot be made as" general purpose tubes but must be specialized for their intendeduses. Thus, forexample; in an oscillator, the reaction elements form integral part ofthe structure and being in the vacuum; practically cannot bereached for modification.

Atubedesigned as-an oscillator; -therefore, is notbeingbest for an aerial feed aIld another for feeding a radio horn, for' exampIe-this means furtherspecialization of tube: design.

This invention seeks to provide aform of con-- struction of a velocity-modulated valve: which shall avoid these disadvantages and give flexibility'of use comparable tothat of an ordinary triod'e or like tube on long waves.

The essential characteristic of the invention lies in separating the elements of the tubeproper and the elements of circuits into: two units: of

independent construction which can be; easily separated: and dismantled from one another so that different circuits. of different shapes and adapted." for diiTerent. requirements may be emp-l'oyed in exchange with one: another in conjunction with the elements of the. tube proper. An arrangement in accordance: with this; invention. thuscomprisestwov parts, viz: the: electronic tube proper and the associated. circuits.

v The inventionis. illustrated in andiurther. ex.- pl'ained in connection with the accompanying, drawings, Figures: 1 to '7'; 7,

Referring to the drawings an arrangement in accordance with this invention comprises two parts constructed as follows: The electronic" tube proper hasa cylindrical glass envelope member A, providedwith welded metallic electrodes and of a diameter: reduced to the minimum dimensions necessary to contain. the well-known cyline drical electron beam: ofa. velocity modulated tube. Within the envelope of" the tube is a cathode I.

and? associated heater I; an intensity controlling grid 2 and two velocity modulating grids 3 and 4 which are in effect extended by two cylindri cal metal parts: 5 and fi sealed to the glass in: such manner that the high frequency electrical connections may be made in a continuous fashion through the whole periphery of a ring 1- or' protruding from the glass. A glass cylinder also forming part of the envelope insulates the two grids from one another. These two electrodesare so shaped in accordance with the inVen-- tion, as to allow the glass to be at a safe dis-' tance' from-the space between the two grids 3 or 4,

where an intense high frequency field exists, so" that harmful dielectric loss is not introduced metal'el'ectrode t2 which finally receives'the electrons. The electrode I2 is cooled by means not shown and may be cooled by radiation" why a current ofwater or air.

In the'modification shown in Figure 2 which isintended for lower powers, the grids 3 and 4:

are replaced we slit l3 cut in the-circuit at the extremity of the bulb as is shown, and the tube itself has a simplified shape. At reduced powers losses in the glass may be disregarded at the positions of the grids 3 and 4 where the high frequency voltage is weak and little trouble is experienced due to the glass at high frequency. The other parts in Figure 2 are marked with Figures 1 and 2. However, research has evolved a resonator which will now be described and which has the following important advantages:

(a) It is electrically and mechanically well- I adapted to the tube.

(b) It permits of a wide variation of wave lengths.

' (c) It is easy to couple to cylindrical feeders of rectangular section which are convenient in many applications such as for supplying travelling waves to radiating horns.

The main feature of these circuits, which form another part of this invention, is that of adapting the mechanical and electronic symmetry of the circuits, not to that of the cylindrical exciting beam, but to that of certain feeders, consisting of hollow metallic guides of rectangular section which serve to conduct the high frequency exciting energy and to conduct away energy amplified by the tube. For this purpose the resonators take the shapeof rectangular boxes B, of length l, breadth a, and depth b. Figure 3 is one example. One of the walls is movable and formed by a piston l3 by which the length Z and thus the resonant wave length of the resonator can be varied. The wall l4 facing the movable .piston is pierced by a rectangular slot I5 which serves to couple the resonator to an external load through the medium of a tube whose rectangular section is varied over a certain length in order to connect it to a rectangular section feeder of constant section without the production of stationary waves. The width of the slot [6 may be adjusted in order to adapt the load to the resonator. The resonator is thus easily adapted to the supply of this type of feeder.

The resonator is also pierced by two holes l6, I! in its walls so as to allow the tube of the invention to pass through. Suitable metal joints ensure contact between the walls I6 and l1 and the rings 1, 8 or l2 which are connected to the tube electrodes. The position of the common axis of the holes in the walls l6 and I! is chosen in relation to the electron beam current in accordance with well known principles so as to adapt the impedance of the cavity as measured between the two centers in question to the impedance of the beam.

Figure 4 shows a resonator according to the invention assembled around the cylindrical envelope of a tube A as already described.

A number of assemblies of circuits with the tubes according to this invention will now be described.

(a) Amplifier.

Figure 5 shows an arrangement with twocircuits B, B and a tube A adapted to operate as a repeater amplifier at the end of a section ofa rectangular wave guide to amplify the power from this feeder and deliveramplified power to a second section of feeder or guide. The advantages of the construction of this invention will be evident from examination of this figure. The construction of the feeders and resonators remains fixed. The tube, on the other hand, which wears out more rapidly, may easily be changed without disarranging the resonators very much. The adjustment of the resonators after changing the tube is easy and only involves a slight adjustment of the position of the pistons by means of the screws [8 and IS.

The same amplifier may be adapted for 00- axial feeders. The slot i5 is then omitted and a coupling loop 28 provided on the wall 2| at the endof the co-axial feeders as in Figure 6.

The component parts of this invention lend themselves readily to the assembly of an oscillator. Figure '7 shows an oscillator so constructed and adapted to supply a rectangular feeder 23. A loop 22 ensures reaction coupling between the two resonators 24 and 25 of the amplifier. The resonator 25 for the grids 3 and 4 is closed. The resonator 24 for the grids l0 and H supplies the feeder 23 through a slot.

Our invention is applicable in ultra-high frequency and super-high frequency bands and has been found to be highly efficient in operation.

We realize however that modifications in details may be made and we desire that it be understood that no limitations upon our invention are intended other than may be imposed by the scope of the appended claims.

What we claim is:

1. A velocity-modulation tube of cylindrical form provided on its external surface with annular velocity modulating electrode outlets, a hollow resonator in the form of a rectangular parallelepipedal box equipped with circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets.

2. A velocity-modulation tube of cylindrical form provided on its external surface with annular velocity modulating electrode outlets, a hollow resonator in the form of a rectangular parallelepipedal box equipped with circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets, a wall of said box being movable and connected with means for pushing it in adjustably in piston-like fashion.

3. A velocity-modulation tube of cylindrical form provided on its external surface with annular velocity modulating electrode outlets, a hollow resonator in the form of a rectangular parallelepipedal box equipped ith circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets, a wall of said box including a slot, and a hollow wave guide connected with said slot.

4. A velocity-modulation tube of cylindrical form provided, on its external surface with an-' nular velocity modulating electrode outlets, a hollow resonator in the form of a rectangular parallelepipedal box equipped with circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets, a wall of said box including a hole connected with the external conductor of a coaxial line whose internal conductor ends in a loop penetrating into the box.

5. A velocity-modulation tube of cylindrical form provided on its external surface with annular electrode outlets for propagating an elec-,

tron beam, a hollow resonator in the form of a rectangular parallelepipedal box equipped with circular holes through hich the body of the said tube passes and Whose edges establish contact with the said electrode outlets, the position of these holes being predetermined by the condition that the impedance of the resonator is adapted to the impedance of the electron beam of the velocity-modulation tube.

6. An amplifier for waves of the ultra-high frequency and super-high frequency bands comprising a velocity-modulation tube of cylindrical form equipped on its external surface with annular electrode outlets, two hollow resonators each in the form of a rectangular parallelepipedal box equipped with circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets, the first resonator being coupled with means of excitation and with the incoming circuit of the tube, and the second resonator being coupled with the outgoing circuit of the tube and with means for tapping energy.

'7. An oscillator for waves of the ultra-high frequency and super-high frequency bands com- 25 prising a velocity-modulation tube of cylindrical form equipped on its external surface with annular electrode outlets, two hollow resonators each in the form of a rectangular parallelepipedal box equipped with circular holes through which the body of the said tube passes and whose edges establish contact with the said electrode outlets, and means establishing a reactive coupling between said two resonators.

ROBERT BONNE.

PIERRE CAI-IOUR.

PIERRE GRIVET.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,113,671 Zottu et al Apr. 12, 1938 2,222,899 Fraenckel Nov. 26, 1940 2,228,939 Zottu et al. Jan. 14, 1941 2,280,026 Brown Apr. 14, 1942 2,312,723 Llewellyn Mar. 2, 1943 2,316,264 Litton Apr. 13, 1943 2,405,611 Samuel Aug. 13, 1946 2,409,608 Anderson Oct. 22, 1946 

